[SPARC64]: Unaligned accesses to userspace are hard errors.

Userspace is forbidden from making unaligned loads and
stores.  So if we get an unaligned trap due to a
{get,put}_user(), signal a fault and run the exception
handler.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 31 insertions, 13 deletions

diff --git a/arch/sparc64/kernel/unaligned.c b/arch/sparc64/kernel/unaligned.c
index a9b765271b85..bc18d480dd1c 100644
--- a/arch/sparc64/kernel/unaligned.c
+++ b/arch/sparc64/kernel/unaligned.c
@@ -243,7 +243,7 @@ static inline int ok_for_kernel(unsigned int insn)
         return !floating_point_load_or_store_p(insn);
 }
 
-static void kernel_mna_trap_fault(void)
+static void kernel_mna_trap_fault(int fixup_tstate_asi)
 {
         struct pt_regs *regs = current_thread_info()->kern_una_regs;
         unsigned int insn = current_thread_info()->kern_una_insn;
@@ -274,18 +274,15 @@ static void kernel_mna_trap_fault(void)
         regs->tpc = entry->fixup;
         regs->tnpc = regs->tpc + 4;
 
-        regs->tstate &= ~TSTATE_ASI;
-        regs->tstate |= (ASI_AIUS << 24UL);
+        if (fixup_tstate_asi) {
+                regs->tstate &= ~TSTATE_ASI;
+                regs->tstate |= (ASI_AIUS << 24UL);
+        }
 }
 
-asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
+static void log_unaligned(struct pt_regs *regs)
 {
         static unsigned long count, last_time;
-        enum direction dir = decode_direction(insn);
-        int size = decode_access_size(insn);
-
-        current_thread_info()->kern_una_regs = regs;
-        current_thread_info()->kern_una_insn = insn;
 
         if (jiffies - last_time > 5 * HZ)
                 count = 0;
@@ -295,6 +292,28 @@ asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
                 printk("Kernel unaligned access at TPC[%lx] ", regs->tpc);
                 print_symbol("%s\n", regs->tpc);
         }
+}
+
+asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
+{
+        enum direction dir = decode_direction(insn);
+        int size = decode_access_size(insn);
+        int orig_asi, asi;
+
+        current_thread_info()->kern_una_regs = regs;
+        current_thread_info()->kern_una_insn = insn;
+
+        orig_asi = asi = decode_asi(insn, regs);
+
+        /* If this is a {get,put}_user() on an unaligned userspace pointer,
+         * just signal a fault and do not log the event.
+         */
+        if (asi == ASI_AIUS) {
+                kernel_mna_trap_fault(0);
+                return;
+        }
+
+        log_unaligned(regs);
 
         if (!ok_for_kernel(insn) || dir == both) {
                 printk("Unsupported unaligned load/store trap for kernel "
@@ -302,10 +321,10 @@ asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
                 unaligned_panic("Kernel does fpu/atomic "
                                 "unaligned load/store.", regs);
 
-                kernel_mna_trap_fault();
+                kernel_mna_trap_fault(0);
         } else {
                 unsigned long addr, *reg_addr;
-                int orig_asi, asi, err;
+                int err;
 
                 addr = compute_effective_address(regs, insn,
                                                  ((insn >> 25) & 0x1f));
@@ -315,7 +334,6 @@ asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
                        regs->tpc, dirstrings[dir], addr, size,
                        regs->u_regs[UREG_RETPC]);
 #endif
-                orig_asi = asi = decode_asi(insn, regs);
                 switch (asi) {
                 case ASI_NL:
                 case ASI_AIUPL:
@@ -365,7 +383,7 @@ asmlinkage void kernel_unaligned_trap(struct pt_regs *regs, unsigned int insn)
                         /* Not reached... */
                 }
                 if (unlikely(err))
-                        kernel_mna_trap_fault();
+                        kernel_mna_trap_fault(1);
                 else
                         advance(regs);
         }